1. Field of the Invention
The present invention relates to a curable polyphenylene ether (PPE) resin, a composition made therefrom, and a process for preparing the resin. More particularly, the present invention relates to a process for preparing a curable polyphenylene ether resin, which involves introducing a vinyl group-containing functional group to the terminal end of PPE.
2. Description of the Prior Art
Communication devices tend to function at higher speeds and frequencies. The substrate material for such devices, such as wireless communication networks, satellite communication equipment, high performance and broadband devices, high speed computers and computer work stations, demands a high glass transition temperature (Tg), low dielectric constant (Dk), and low loss factor (Df). Presently, the copper-clad laminate used for printed circuit boards (PCB) is mainly FR-4, and the substrate of which is made of epoxy resin. However, electrical properties (such as Dk and Df) of FR-4 can no longer meet the increasing needs of high frequency.
Polyphenylene ether (PPE), having high Tg and superior electrical properties, is a potential material for high frequency substrates. However, PPE is a thermoplastic resin and is poor in solvent resistance. Therefore, there is a need to modify PPE into a thermosetting resin so as to increase the solvent resistance and heat resistance properties.
In order to improve the solvent resistance and heat resistance of PPE, Asahi Company in EP 382,312 uses a composition including allylated PPE (APPE), triallyl isocyanurate (TAIC), and PH25B (an initiator) to fabricate a substrate. First, PPE is subjected to dehydrogenation of side chain methyl (xe2x80x94CH3) by using n-butyl lithium (n-BuLi), which is then reacted with CH2xe2x95x90CHCH2X (wherein X=Cl, Br, or I) so as to modify the side chain into xe2x80x94CH2CH2CHxe2x95x90CH2. Thus, a curable PPE resin is obtained. Since the process involves using n-BuLi to conduct dehydrogenation of xe2x80x94CH3, the preparation is not easy and the cost is high.
An object of the present invention is to solve the above-mentioned problems and to provide an easy and inexpensive process for preparing a curable polyphenylene ether resin.
Another object of the present invention is to provide a novel curable polyphenylene ether resin.
A further object of the present invention is to provide a novel polyphenylene ether resin composition, which can be used in preparing pre-pregs and copper-clad laminates for printed circuit boards.
To achieve the above objects, the process for preparing a curable polyphenylene ether resin of the present invention includes:
reacting a polyphenylene ether resin respresented by formula (I), a strong base, and a compound containing a leaving group and vinyl group to obtain a curable polyphenylene ether resin represented by formula (II), wherein formula (I) is: 
wherein
R1 can be the same or different and is selected from the group consisting of H, alkyl having from 1 to 3 carbon atoms, and 
wherein
R11 is alkylene having from 1 to 3 carbon atoms, and R12 is aryl;
Z1 can be the same or different and is selected from the group consisting of H, OH, and 
xe2x80x83and at least one Z1 is OH or 
wherein
R13 is aryl;
p is from 2 to 165,
wherein the compound containing leaving group and vinyl group has the formula (A) or (B): 
wherein
X is a leaving group selected from the group consisting of halogen and sulfonate;
A is selected from the group consisting of C1-8 ethers, C1-8 amines, C1-8 amides, and C1-8 esters;
n is 1 or 2; and
m is 0 or an integer of from 1 to 6,
wherein formula (II) is 
wherein
R2 can be the same or different and is selected from the group consisting of H, alkyl having from 1 to 3 carbon atoms, 
wherein
R11 is alkylene having from 1 to 3 carbon atoms;
R12 is aryl;
A is selected from the group consisting of C1-8 ethers, C1-8 amines, C1-8 amides, and C1-8 esters;
n is 1 or 2; and
m is 0 or an integer of from 1 to 6;
Z2 can be the same or different and is selected from the group consisting of H, OH, 
xe2x80x83and at least one Z2 is the group represented by formula (i) or (ii), wherein R13 is aryl, and A, n, m are defined as above;
p is from 2 to 165.